In many mechanical systems, it is often necessary to provide an actuator that can be used to activate a certain component or functions when an emergency arises. One specific example is to bring an elevator car to a stop. Current available technologies accomplish this task by using electrically, hydraulically or pneumatically powered sources. This approach is unsatisfactory because of the inherent complexity of the systems using these types of powered sources which reduces their reliability. Accordingly, there is a need in the industry to provide a novel device that can be used to provide or perform an emergency function and which is simple and more reliable than prior art systems.